再论“田中线”和“滇西—滇东南生态地理（生物地理）对角线”的真实性和意义
摘要
Based on comparative studies on four regional floras from northwest, west, south and southeast of Yunnan separately, the significances of two biogeographical lines:Tanaka Line and Ecogeographical Diagonal line both going from northwest to southeast of Yunnan, are discussed. At family and generic levels, similarity coefficients among the four comparative floras are more than 93% and 60% separately, which indicates the close floristic affinities among them. The highest similarity coefficient, i.e. 98.7% in family level and 78.6% in generic level respectively, is found between the regional flora from northwest Yunnan and the flora from southeast Yunnan although the two regions are far away from each other. The regional flora from northwest Yunnan is also the most similar to the regional flora from southeast Yunnan in floristic composition. These results support the idea of Ecogeographical Diagonal line. At specific level, the relatively high similarity coefficient is between the regional flora of west Yunnan and the one of south Yunnan. The floristic affinities among the regional floras and distribution patterns of some taxa could be explained by the geological history of Yunnan and the tectonic theory.